Experimental Studies Of NO_x Reduction By Micronized Coal Reburning

Pollutant NOx emitted by coal combustion power plant is an increasing threat to environment and human health, which becomes an urgent problem to be solved. Many efficient methods have been developed for solving the NOx emission problem in world wide, one of them is coal reburning. In this paper, pulverized coal reburning technology is brought forward and a lot of researches are carried out aiming at the key issues of fuel reburning such as NOx reduction efficiency and burnout rate.After surveying many coal-burnt-furnace inside of our country, a one-dimensional test system with multi-function is designed and built up. This system is a pilot-scale facility and can get instructive results for business utility. With this testing-bed, research for pulverized coal burning or micronized coal reburning can been put in practice, productive and reductive process of NOx can be simulated in this furnace.The results of the change tendency of pulverized coal character with particle diameter are got from particle diameter determining test, hole structure analysis test and TG analysis test in this paper. And research on physics and combustion characteristic of micronized coal is putted off, which provide a basis for researching reburning process and burnout of particle with micronized coal reburning.Using this system, researches on NOx emission with coal reburning are carried out. The results of influence on NOx emission by coal type, coal particle diameter, furnace temperature and excess air are reached through experiences. Based on these, micronized coal reburning tests are processed, and also the influence on NOx emission by coal type, coal particle diameter, furnace temperature, excess air and residence time, which show a slightly effect results on NOx reduction.But with the height limitation of test bed, a few experiences for burnout are gone on, not for abroad investigation. Calculate with simplified model and numerical simulation for burnout of coal are discussed. Study shows that particle diameter, oxygen and temperature of combustion environment play an important role on burnout or time for burnout of coal.